Bioavailability of oxycodone after administration of a new prolonged-release once-daily tablet formulation in healthy subjects, in comparison to an established twice-daily tablet

Oxycodone, Morphine, and Fentanyl in Patients With Chronic Pain: Proposal of Dose-Specific Concentration Ranges

BACKGROUND

Interpreting opioid concentrations is challenging because of the lack of reference ranges. Therefore, the authors aimed to propose dose-specific concentration ranges in serum for oxycodone, morphine, and fentanyl in patients with chronic pain, based on concentration measurements from a large number of patients and supported by theoretical pharmacokinetic calculations and previously published concentrations.

METHODS

The opioid concentrations in patients undergoing therapeutic drug monitoring (TDM) for various indications (TDM group) and patients with cancer (cancer group) were investigated. Patients were divided based on the daily opioid doses, and the 10th and 90th percentiles of the concentrations in each dose interval were evaluated. In addition, the expected average serum concentrations were calculated for each dose interval based on published pharmacokinetic data, and a targeted literature search for previously reported dose-specific concentrations was performed.

RESULTS

The opioid concentrations in 1054 patient samples were included: 1004 in the TDM group and 50 in the cancer group. In total, 607 oxycodone, 246 morphine, and 248 fentanyl samples were evaluated. The authors proposed dose-specific concentration ranges based mainly on 10th-90th percentiles of the concentrations measured in patient samples, whereas the calculated average concentrations and previously published concentrations were used to adjust the ranges. In general, results from calculations and concentrations retrieved from previous literature were within the 10th-90th percentiles of concentrations from patient samples. However, the lowest calculated average concentrations of fentanyl and morphine were below the 10th percentiles of patient samples in all dose groups.

CONCLUSIONS

The proposed dose-specific ranges may be useful for interpreting steady-state opioid serum concentrations in clinical and forensic settings.

Oxycodone alleviates mifepristone-stimulated human endometrial stromal cell injury by activating the Keap1/Nrf2/HO-1 signaling pathway

BACKGROUND

Endometrial injury is a common disease in women caused by intrauterine inflammation, infections, and endocrine disorders. Human endometrial stromal cells (hEndoSCs) can maintain endometrial homeostasis and play an important role in repairing endometrial injury. Mifepristone, a steroidal anti-progesterone drug, is widely used in the field of reproductive medicine worldwide. Mifepristone-induced hEndoSC injury has been used to study endometrial injury in vitro. At present, the pathogenesis and potential regulatory mechanisms of oxycodone in endometrial injury remain unknown.

AIMS

We aimed to evaluate the functions of oxycodone in mifepristone-stimulated hEndoSC injury and analyze its potential molecular mechanism.

MATERIALS & METHODS

hEndoSC viability, cytotoxicity, and apoptosis were analyzed using the methyl thiazolyl tetrazolium assay, the lactate dehydrogenase assay, and flow cytometry, respectively. Furthermore, the levels of cleaved-Caspase3, Keap1, Nrf2, HO-1, and NQO1 were assessed using reverse transcription quantitative polymerase chain reaction and western blot analysis, and the release of inflammatory cytokines was determined using the enzyme-linked immunosorbent assay.

RESULTS

We observed that oxycodone had no adverse effects on hEndoSCs; rather, it protected hEndoSCs against mifepristone-induced endometrial damage, as confirmed by the enhanced cell viability, reduced number of apoptotic cells, decreased Caspase3 activity and inflammatory cytokine secretion, and increased Keap1/Nrf2/HO-1 pathway-related protein expression. In addition, we found that the protective effects of oxycodone on mifepristone-induced hEndoSC injury were inhibited by ML385 (a Keap1/Nrf2/HO-1 inhibitor).

CONCLUSION

In summary, we confirmed that oxycodone alleviates mifepristone-induced hEndoSC injury by activating the Keap1/Nrf2/HO-1 signaling pathway.

Oxycodone Alleviates Endometrial Injury via the TLR4/NF-κB Pathway

Endometrial injury is a common female disease. This study was designed to illustrate the effects of oxycodone on mifepristone-induced human endometrial stromal cells (hEndoSCs) injury and delineate the underlying molecular mechanism. hEndoSCs were stimulated with mifepristone to generate the endometrial injury in vitro model. hEndoSCs viability, cytotoxicity, and apoptosis were measured by methyl thiazolyl tetrazolium (MTT) assay, lactate dehydrogenase assay (LDH), and flow cytometry (FCM) analysis, respectively. Meanwhile, quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot assay were conducted to evaluate gene and protein expressions. The secretions of inflammatory cytokines (TNF-α, IL-1β, and IL-6) were measured using enzyme-linked immunosorbent assay (ELISA). The data revealed that mifepristone exposure memorably inhibited hEndoSCs viability and promoted cell apoptosis and inflammatory cytokines secretion, and oxycodone had no cytotoxicity on hEndoSCs. Oxycodone increased hEndoSCs growth, blocked cell apoptosis, enhanced Bcl-2 expression, reduced Bax levels, and decreased the secretion of inflammatory cytokines in mifepristone-induced hEndoSCs, exhibiting the protective effects in endometrial injury. In addition, the TLR4/NF-κB pathway-related protein levels (TLR4 and p-p65) in mifepristone-treated hEndoSCs were enhanced, while these enhancements were inhibited by oxycodone treatment. In conclusion, oxycodone exhibited the protective role in mifepristone-triggered endometrial injury via inhibiting the TLR4/NF-κB signal pathway.

Regular dosing compared with as-needed dosing of opioids for management of chronic cancer pain: systematic review and meta-analysis

Opioids are the recommended form of analgesia for patients with persistent cancer pain, and regular dosing "by the clock" is advocated in many international guidelines on cancer pain management. The development of sustained-release opioid preparations has made regular dosing easier for patients. However, patients report that the intensity and impact of their cancer pain varies considerably day to day, and many try to find a trade-off between acceptable pain control and impact of cognitive (and other) adverse effects on daily activities. In acute care settings, (eg, postoperative) as-needed dosing and other opioid-sparing approaches have resulted in better patient outcomes compared with regular dosing. The aim of this study was to determine whether regular dosing of opioids was superior to as-needed dosing for persistent cancer pain. We systematically searched for randomised controlled trials that directly compared pain outcomes from regular dosing of opioids with as-needed dosing in adult cancer patients. We identified 4347 records, 25 randomised controlled trials meet the inclusion criteria, 9 were included in the review, and 7 of these included in meta-analysis. We found no clear evidence demonstrating superiority of regular dosing of opioids compared with as-needed dosing in persistent cancer pain, and regular dosing was associated with significantly higher total opioid doses. There was, however, a paucity of trials directly answering this question, and low-quality evidence limits the conclusions that can be drawn. It is clear that further high-quality clinical trials are needed to answer this question and to guide clinical practice.

Oxycodone stimulates normal and malignant hematopoietic progenitors via opioid-receptor-independent-β-catenin activation

Oxycodone is a common type of opioid used for the treatment of moderate to severe pain. Besides its analgesic effects on neuron cells, the effects of oxycodone on other cell types are yet to be elucidated. We previously demonstrated that oxycodone displayed both pro- and anti-cancer effects on bulk cancer cells. This work further investigated the effects of oxycodone on normal and malignant hematopoietic stem cells. Using hematopoietic CD34⁺ cells isolated from normal bone marrow (NBM) or patients with acute myeloid leukemia (AML), we showed that oxycodone activates hematopoietic cells regardless of cell development stage and malignant status. Oxycodone dose-dependently increases colony formation and self-renewal capacity of NBM and AML stem/progenitor cells, and promotes proliferation of AML bulk cells. NBM stem/progenitor cells are more sensitive to oxycodone than AML counterparts. In addition, oxycodone alleviates chemotherapy drug-induced toxicity in AML stem/progenitor cells. Mechanism studies demonstrate that oxycodone acts on hematopoietic cells in an opioid-receptor-independent manner. Oxycodone did not affect epithelial growth factor receptor (EGFR) signaling neither but stimulated Wnt/β-catenin signaling. Rescue studies via depleting β-catenin using genetic and pharmacological approaches confirmed that β-catenin was required for the activation of hematopoietic cells induced by oxycodone. Our work demonstrates 1) the protective role of oxycodone in malignant hematopoietic cells from chemotherapy; 2) stimulatory effects of oxycodone in normal hematopoietic stem cells; and 3) ability of oxycodone in Wnt signaling activation.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

Once-Daily Oxycodone Prolonged-Release Tablets Are Resistant to Alcohol-Induced Dose Dumping: Results From a Randomized Trial in Healthy Volunteers

The objective of this study was to determine the effect of concomitant alcohol intake on the bioavailability of oxycodone from an oxycodone once-daily (OOD) formulation and an oxycodone twice-daily (OTD) formulation. A phase I, open-label, randomized, crossover alcohol interaction study in 20 healthy volunteers under fasting conditions was conducted. Participants received five treatments, OOD with 240 mL of 0%, 20%, or 40% alcohol; and OTD with 240 mL of 0% or 40% alcohol. Pharmacokinetic parameters did not differ between participants taking OOD with water or with 240 mL of 20% alcohol. There was a slight increase in overall oxycodone absorption from OOD with 40% alcohol but no increase in peak absorption. Oxycodone absorption from OTD showed peak and overall increases with 40% alcohol but maintained a prolonged-release profile. Although it is recommended that alcohol be avoided while taking opioids, there was no evidence of alcohol-induced dose dumping in these oxycodone formulations.